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Biomedical subjects

Y Nagata

Publications and source records attributed to Y Nagata.

At least 73 records · Page 4Linked to original sources
PubMed2001

Waist to hip circumference ratio as a significant predictor of preeclampsia, irrespective of overall adiposity.

OBJECTIVE: To investigate whether abnormal body fat distribution is a significant predictor of the development of preeclampsia, irrespective of overall adiposity. METHODS: Twenty-six women with preeclampsia and 198 control women were enrolled. Waist to hip circumference ratio (WHR), body weight (BW), and body mass index (BMI, wt/ht2) were measured early in pregnancy (< 9 weeks of gestational age). Age, height, parity, tobacco usage, education period, gestational duration, and weight gain during pregnancy were also recorded for each subject. RESULTS: WHR, BMI, and BW early in pregnancy were significantly higher in the preeclampsia group (p < 0.0001). WHR, BMI, and BW positively correlated with the development of preeclampsia on univariate regression analysis (Standardized regression coefficient = 0.410, 0.387, and 0.363, respectively, p < 0.0001). On stepwise multiple regression analysis, WHR still correlated with the development of preeclampsia irrespective of BMI and BW. When the WHR predictive of the development of preeclampsia was set at 0.9, the sensitivity was 46.2% (12/26), which was significantly better than that of 25 of BMI (19.2%, 5/26; p < 0.05). CONCLUSION: Higher WHR is a significant predictor of the development of preeclampsia. This relation is irrespective of overall adiposity.

Adipose Tissue↗
PubMed2001

A lectin from an ascomycete mushroom, Melastiza chateri: no synthesis of the lectin in mycelial isolate.

Using an affinity adsorbent prepared from L-fucose and starch, a lectin was isolated from fruit bodies of an ascomycete mushroom, Melastiza chateri. The lectin was found to cross-react with antiserum against Aleuria aurantia lectin (AAL), that had been obtained from another ascomycete mushroom. The N-terminal amino acid sequence was analyzed, and among 20 residues 12 were the same as AAL. The molecular mass of the lectin estimated by SDS-PAGE was approximately 40 kDa, which is larger than that of AAL. Mycelial isolate was obtained from M. chateri by germinating ascospores, and identified by analyzing restriction fragment length polymorphisms (RFLP) of DNA. The isolate from M. chateri did not synthesize the lectin, although the isolate from A. aurantia had been known to synthesize AAL as much as the fruit body.

Amino Acid Sequence↗
PubMed2001

Domain construction of cherry-tomato lectin: relation to newly found 42-kDa protein.

In the early stage of ripening of cherry-tomato fruits (Lycopersicon esculentum var. cherry), the lectin activity increased logarithmically and reached a plateau at day 10 after flowering. During purification of lectin from ripe and unripe fruits, a 42-kDa protein was found abundantly in unripe fruits. The protein cross-reacted with anti-cherry-tomato-lectin serum, retained chitin-binding ability, but showed no lectin activity. Comparative studies between the structure of the lectin and the 42-kDa protein were done. N-Terminal amino acid sequences of the lectin, peptides derived from the S-pyridylethylated lectin, and fragments generated by limited proteolysis of the native lectin showed that the lectin was comprised of three domains, Hyp-rich, Cys-rich, and Gln-rich, and the alignment of them was as this order from the N-terminus. Studies on the 42-kDa protein showed that it contained two of the three domains, Cys-rich and Gln-rich, but the amino acid sequence analysis showed that the protein should be a product of another gene.

Amino Acid Motifs↗
PubMed2001

A mucinous histochemical study on malignancy of aberrant crypt foci (ACF) in rat colon.

The relationship between malignancy and number of crypts (crypt multiplicity) comprising aberrant crypt foci (ACF) was investigated, by studying changes in the mucous nature of ACF with 5 crypts or less, ACF with 6-13 crypts, adenomas and invasive adenocarcinomas induced by 1,2-dimethylhydrazine in distal colon of rats. A paradoxical Con A-staining was performed for goblet cell mucins. Of the sulfomucin-dominant ACF with 1-3 crypts, 82.6% had labile class III mucin, similar to the distal colon in the normal rats. However, in most of the goblet cell mucin produced by the ACF with 4-5 crypts with an indicated relation to colorectal carcinoma or the sialomucin (SiM) -dominant ACF with 1-3 crypts, mucin types other than class I were rarely present. The incidence of class I mucin decreased with the increase in crypt multiplicity of ACF or in the degree of histological malignancy, with the lowest incidence of 40% in adenocarcinomas. In contrast, the incidence of class II mucin increased markedly with the increase in crypt multiplicity of ACF or in the degree of histological malignancy, with the highest incidence in adenocarcinomas (95%). The ACF with 6-13 crypts had a mucous profile similar to that of adenomas. These results suggested that malignancy of ACF related to the crypt multiplicity. In the ACF with 1-3 crypts, SiM-dominant ACF had the potential to progress to malignant lesions.

Adenocarcinoma, Mucinous↗
PubMed2001

Perioperative changes in circulating leptin levels in women undergoing total abdominal hysterectomy.

To investigate the effects of total abdominal hysterectomy on circulating leptin levels, 16 pre- and 8 postmenopausal patients with uterine leiomyoma or carcinoma in situ of the uterine cervix were enrolled. Serum levels of leptin and fasting blood sugar (FBS) were determined before (day -7) and after surgery (day +1 and +7). Body mass index (BMI) was recorded at day -7 and +7. Anesthesia duration, surgical duration, hematology, and blood loss during surgery were recorded. Relations of these variables to serum leptin levels were investigated. Serum leptin levels rose from 7.3+/-4.7 ng/mL to 9.3+/-5.8 ng/mL at day +1 (P < 0.01), then decreased to 4.9+/-3.0 ng/mL at day +7 (P < 0.05 vs. values at day -7 and +1). FBS levels also rose from 89.4+/-7.5 mg/dL to 119.3+/-24.0 mg/dL (P < 0.01), then returned to normal at day +7 (96.2+/-9.0 mg/dL). However, there was no significant correlation observed between FBS and leptin levels at each time point (r < or = 0.22). BMI decreased from 22.7+/-3.0 kg/m2 to 21.7+/-2.9 kg/m2 at day +7 (P < 0.001). At day -7 and +7, leptin levels were positively correlatd with BMI (r = 0.79, P < 0.001 and r = 0.71, P < 0.001, respectively). Circulating leptin levels were increased on day one after total abdominal hysterectomy.

Adult↗
PubMed2001

Relationships among serum testosterone levels, body fat and muscle mass distribution in women with polycystic ovary syndrome.

We investigated the relationships among serum testosterone levels, body fat and muscle mass distribution in women with polycystic ovary syndrome (PCOS). Subjects were 67 women with PCOS (mean age +/- standard deviation, 28.8 +/- 6.6 years). Baseline characteristics included age and height. Trunk-leg fat ratio and trunk-leg muscle ratio were assessed with dual-energy x-ray absorptiometry. Serum testosterone and dehydroepiandrosterone sulfate levels were measured with radioimmunoassays. Relationships among serum testosterone levels, body fat and muscle mass distribution were investigated using Pearson and partial correlation tests. Serum testosterone levels were positively correlated with trunk-leg fat ratio (r = 0.398, P < 0.01), but were inversely correlated with trunk-leg muscle ratio (r = -0.332, P < 0.05). Trunk-leg muscle ratio was inversely correlated with trunk-leg fat ratio (r = -0.360, P < 0.01). Serum testosterone levels were still correlated with trunk-leg fat ratio (r = 0.500, P < 0.001) and trunk-leg muscle ratio (r = -0.286, P < 0.05), after adjusting for age and height. Trunk-leg fat ratio was still correlated with trunk-leg muscle ratio, after adjusting for age, height, and serum testosterone levels. Based on these results, we concluded that higher serum testosterone levels may contribute to the upper body fat distribution and peripheral muscle mass distribution. In addition, peripheral muscle mass distribution may also contribute to the upper body fat distribution.

Absorptiometry, Photon↗
PubMed2001

Meta-analysis of multiple myeloma and benzene exposure.

Epidemiologic studies have suggested that benzene exposure may be a risk factor of multiple myeloma (MM). We performed meta-analyses of case-control studies to assess the association between occupational exposure to benzene and the risk of MM. We divided the occupational sources of benzene exposure into 4 categories, benzene and/or organic solvents, petroleum, petroleum products, and engine exhaust, for conducting the meta-analysis. As a result, a significant positive association was indicated between exposure to engine exhaust and MM (summary odds ratio or summary OR=1.34, 95% confidence interval or 95%CI=1.14-1.57). However, no significant associations were obtained for benzene and/or organic solvents (summary OR=0.74, 95%CI=0.60-0.90), petroleum (summary OR=1.11, 95%CI=0.96-1.28) and petroleum products (summary OR=1.08, 95%CI=0.89-1.33) with risk of MM. These results suggested that benzene exposure itself was not likely to be a risk factor of MM. It is thought that several harmful chemical agents in engine exhaust, other than benzene, could be etiologically related to the risk of MM. Further case-control studies on MM are needed to obtain more information about detailed occupational exposure to toxic substances.

Air Pollutants, Occupational↗
PubMed2001

[Usefulness of routine ophthalmologic examination for cytomegalovirus retinitis in acquired immunodeficiency syndrome patients].

PURPOSE: To evaluate the usefulness of routine ophthalmologic examinations for cytomegalovirus retinitis in acquired immunodeficiency syndrome (AIDS) patients. METHODS: Clinical symptoms of cytomegalovirus (CMV) retinitis in patients with AIDS who had circulating CD4+ T lymphocytes 50/microliter or less and received monthly ophthalmological examinations (examined group) were compared with those of the patients detected by non-routine ophthalmological examinations (unexamined group). RESULTS: The patients in whom early CMV retinitis was detected by monthly ophthalmological examinations had no subjective symptoms or iritis. The size of CMV retinitis was smaller than 2 disc diameters and it did not extend to the papillomacular area in a majority of the patients. On the other hand, the size of CMV retinitis in the unexamined group was larger than 10 disc diameters and it extended to the papillomacular area in most cases. The visual prognosis of the examined group was better than that of the unexamined group. CONCLUSIONS: To protect visual acuity, it is important to conduct monthly ophthalmological examinations in patients with AIDS whose serum CD4+ T lymphocyte counts are 50 cells/microliter or less.

AIDS-Related Opportunistic Infections↗
PubMed2001

[Ocular complications in patients infected with human immunodeficiency virus seen at the Acquired Immunodeficiency Syndrome Clinical Center].

PURPOSE: To examine the ocular complications in patients infected with human immunodeficiency virus(HIV) in Japan. METHODS: The medical records of 322 patients seen at the acquired immunodeficiency syndrome(AIDS) Clinical Center from July 1, 1997 through December 31, 1998 were reviewed, and the HIV-associated ocular complications were correlated with serum CD 4+ T-lymphocyte counts. RESULTS: Ocular complications were found in 51 patients: 35 cases with retinal microvasculopathy, 17 cases with cytomegalovirus retinitis(9 quiescent, 6 active, and 2 recurrent), and 1 case each with tuberculous uveitis, phthisis bulbi after necrotizing herpetic retinopathy, conjunctival Kaposi's sarcoma, papilledema, divergence palsy, hemianopia, and abducens palsy. Retinal microvasculopathy was present in patients with CD 4+ T-lymphocyte counts above 500/mm3, but was more common in patients with cell counts below 200/mm3. Among 6 patients with active cytomegalovirus retinitis, 5 patients had a CD 4+ T-lymphocyte count below 50/mm3 at the onset of retinitis, while one patient developed retinitis after the cell count increased to over 200/mm3 with highly active antiretroviral therapy. CONCLUSION: Cytomegalovirus retinopathy may occur in patients with a CD 4+ T-lymphocyte count of more than 200/mm3.

AIDS-Related Opportunistic Infections↗
PubMed2001

[Surgery of anterior communicating artery aneurysms with the perforating artery branching from the dome].

The authors have treated two cases of anterior communicating artery aneurysms with the perforating artery branching from the top of the dome. Case 1 was a 32-year-old female. She developed sudden-onset of headache while sleeping. Angiography showed an anterior communicating artery aneurysm with its dome directed upward. The left pterional approach was utilized, and a rather thick perforating artery was found branching from the top of the dome and going upward. Neck clipping of the aneurysm was performed resulting in interruption of the blood flow of the perforating artery. The patient showed no neurological deficit postoperatively. Case 2 was a 67-year-old female. She suffered from sudden-onset of headache and was transferred from another hospital to the author's care. Three-dimensional CT angiography revealed an anterior communicating artery aneurysm with its dome directed in the anterior-superior direction. A rather thick perforating artery was coming off the top of the dome. Neck clipping was carried out, but permanent memory impairment appeared postoperatively. The perforating arteries coming off the anterior communicating artery have been called the hypothalamic arteries. In 1994, Serizawa et al divided these arteries into three groups. One is the subcallosal artery, which gives blood flow not only to the hypothalamus but also to the subcallosal area. The other two are the hypothalamic and chiasmatic arteries. The authors consider that this nomenclature of those arteries is suitable in practical use for surgery, because these arteries have different vessel sizes, they originate from the anterior communicating artery, and supply different territories with blood. Since the septal nuclei are in the subcallosal area, interruption of blood flow of the subcallosal artery by the clipping of an aneurysm may result in memory impairment caused by damage to the septal nuclei. Serizawa et al also reported that some branches are coming from the A2-segment to the subcallosal area as collateral circulation. In the author's two cases, the perforating arteries branching from the top of the domes were considered to be subcallosal arteries, because their size was rather thick and the arteries were going upward directed probably to the subcallosal area. Memory impairment in case 2 was considered a natural outcome due to the interruption of blood flow of the subcallosal artery by the clipping of the aneurysm. On the other hand, in case 1, sufficient collateral blood flow from A2 to the subcallosal area might have prevented damage to the septal nuclei, probably because of the insufficient size of the subcallosal artery. In these rare cases, dome clipping and coating should be the first choice of treatment, because prognosis after dome clipping of the aneurysm with coating was rather satisfactory.

Adult↗
PubMed2001

Structure-specificity relationships for haloalkane dehalogenases.

A structural analysis of the substrate specificity of hydrolytic dehalogenases originating from three different bacterial isolates has been performed using the multiple computer-automated structure evaluation methodology. This methodology identifies structural fragments in substrate molecules that either activate or deactivate biological processes. The analysis presented in this contribution is based on newly measured dehalogenation data combined with data from the literature (91 substrates). The enzymes under study represent different specificity classes of haloalkane dehalogenases (haloalkane dehalogenase from Xanthobacter autotrophicus GJ10, Rhodococcus erythropolis Y2, and Sphingomonas paucimobilis UT26). Three sets of structural rules have been identified to explain their substrate specificity and to predict activity for untested substrates. Predictions of activity and inactivity based on the structural rules from this analysis were provided for those compounds that were not yet tested experimentally. Predictions were also made for the compounds with available experimental data not used for the model construction (i.e., the external validation set). Correct predictions were obtained for 28 of 30 compounds in the validation set. Incorrect predictions were noted for two substrates outside the chemical domain of the set of compounds for which the structural rules were generated. A mechanistic interpretation of the structural rules generated provided a fundamental understanding of the structure-specificity relationships for the family of haloalkane dehalogenases.

Biodegradation, Environmental↗
PubMed2001

Advanced bladder cancer in a young female: a case report.

We present a rare case of advanced bladder cancer in a young female. A 27-year-old woman had the chief complaint of proteinuria. A clinical examination revealed a papillary, broad-based bladder tumor with a clinical stage of T3, N3, M0. Preoperatively, 3 courses of neoadjuvant chemotherapy with methotrexate, adriamycin, and cisplatin were performed, and proved to be effective. Radical cystectomy was done and the histopathologically it was diagnosis as Grade 2 transitional cell carcinoma, which did not show any p53 gene mutation. The patient's postoperative clinical course was uneventful, and she remained disease free for 27 months. Bladder carcinoma in patients under 30 years of age tends to have a early stage and a low grade. However, the above described 27-year-old female patient demonstrated the advanced stage bladder tumor. Therefore, it should be kept in mind to accurately evaluate young patients with transitional cell carcinoma of the bladder and not to rule out the possibility of advanced disease even though a patient is young.

Adult↗
PubMed2000

The long-term evolutions and the regional characteristics of atmospheric methane concentrations in Nagoya, 1983-1997.

This study provides information on the long-term evolutions of the atmospheric methane (CH4) concentrations in Nagoya City, Japan, which were analyzed by using the continuous monitoring data observed at the eight observatory stations for 1983-1997. The 15-year records of the atmospheric CH4 concentrations were examined by means of a time-series analysis using a fast Fourier transform with a low-pass filter to elucidate the seasonal cycles and the long-term trends. The annual averages of the CH4 concentrations in Nagoya were 1.85 ppmv (parts per million by volume), 1.91 ppmv, and 1.90 ppmv in 1988, 1995 and 1997, respectively. Moreover, the annual average growth rate showed a drastic decrease from 17 ppbv (parts per billion by volume) year(-1) in 1992 to 2 ppbv year(-1) in 1993, and further down to 7 ppbv year(-1) in 1997. Comparison of the atmospheric CH4 records in Nagoya with those in global air of the northern hemisphere observed at Mauna Loa observatory in Hawaii, USA, allows us to estimate the excess concentration of CH4 in the urban atmosphere of Nagoya, which was 0.17 ppmv in 1988 and 0.15 ppmv in 1997. On a local scale, the atmospheric CH4 concentrations in the northern part of Nagoya City increased until 1992 and then gradually decreased from 1993 to 1997, although those in the south-western urban areas constantly increased at the averaged growth rate of 13 ppbv year(-1) for 1988-1997. The variation of the long-term trends of the CH4 concentrations in Nagoya may be ascribed to the emission changes from the CH4 sources due to the human activities such as waste dumping and landfills.

Air Pollution↗
PubMed2000

Reaction mechanism and stereochemistry of gamma-hexachlorocyclohexane dehydrochlorinase LinA.

gamma-Hexachlorocyclohexane dehydrochlorinase (LinA) catalyzes the initial steps in the biotransformation of the important insecticide gamma-hexachlorocyclohexane (gamma-HCH) by the soil bacterium Sphingomonas paucimobilis UT26. Stereochemical analysis of the reaction products formed during conversion of gamma-HCH by LinA was investigated by GC-MS, NMR, CD, and molecular modeling. The NMR spectra of 1,3,4,5,6-pentachlorocyclohexene (PCCH) produced from gamma-HCH using either enzymatic dehydrochlorination or alkaline dehydrochlorination were compared and found to be identical. Both enantiomers present in the racemate of synthetic gamma-PCCH were converted by LinA, each at a different rate. 1,2,4-trichlorobenzene (1,2,4-TCB) was detected as the only product of the biotransformation of biosynthetic gamma-PCCH. 1,2,4-TCB and 1,2,3-TCB were identified as the dehydrochlorination products of racemic gamma-PCCH. delta-PCCH was detected as the only product of dehydrochlorination of delta-HCH. LinA requires the presence of a 1,2-biaxial HCl pair on a substrate molecule. LinA enantiotopologically differentiates two 1,2-biaxial HCl pairs present on gamma-HCH and gives rise to a single PCCH enantiomer 1,3(R),4(S),5(S),6(R)-PCCH. Furthermore, LinA enantiomerically differentiates 1,3(S),4(R),5(R),6(S)-PCCH and 1,3(R),4(S),5(S),6(R)-PCCH. The proposed mechanism of enzymatic biotransformation of gamma-HCH to 1,2,4-TCB by LinA consists of two 1,2-anti conformationally dependent dehydrochlorinations followed by 1,4-anti dehydrochlorination.

Bacterial Proteins↗
PubMed2000

Crystal structure of the haloalkane dehalogenase from Sphingomonas paucimobilis UT26.

The haloalkane dehalogenase from Sphingomonas paucimobilis UT26 (LinB) is the enzyme involved in the degradation of the important environmental pollutant gamma-hexachlorocyclohexane. The enzyme hydrolyzes a broad range of halogenated cyclic and aliphatic compounds. Here, we present the 1.58 A crystal structure of LinB and the 2.0 A structure of LinB with 1,3-propanediol, a product of debromination of 1,3-dibromopropane, in the active site of the enzyme. The enzyme belongs to the alpha/beta hydrolase family and contains a catalytic triad (Asp108, His272, and Glu132) in the lipase-like topological arrangement previously proposed from mutagenesis experiments. The LinB structure was compared with the structures of haloalkane dehalogenase from Xanthobacter autotrophicus GJ10 and from Rhodococcus sp. and the structural features involved in the adaptation toward xenobiotic substrates were identified. The arrangement and composition of the alpha-helices in the cap domain results in the differences in the size and shape of the active-site cavity and the entrance tunnel. This is the major determinant of the substrate specificity of this haloalkane dehalogenase.

Binding Sites↗